The present invention generally relates to harvester tines.
A typical harvester includes a harvester platform including a frame supported for movement over ground, the frame having a front edge, a cutter bar extending along the front edge, and a pickup reel for lifting up crop into the harvester. In general, the pickup reel includes a reel support supported by the frame, a reel shaft rotatably supported by the reel support and extending along an axis transverse to the frame, and a plurality of arms extending radially from and being rotatable with the shaft. The pickup reel also includes a plurality of second shafts or bat tubes, each supported by at least one arm and being generally parallel to and radially spaced from the reel shaft, the bat tubes being rotatable relative to and rotatable with the arm, and a plurality of harvester tines supported by each bat tube for movement with the bat tube. During operation of the pickup reel, the tines engage the crop and lift it into the harvester.
Most conventional tines are injection molded, formed of a polymer, and have a parting line which is lateral. Conventional injection molded pickup reel polymer tine designs typically use a lateral parting line in the mold because that is the easiest way to build a mold for the traditional curved shape and integral tube bore. When a tine has a wrap-around feature that allows it to be fastened to a tubular bat section, it must be molded so the wrap-around has an integral tube bore that matches the diameter of the tubular bat section. Using a lateral parting line provides for a simple molding process, as the bore in the wrap-around runs in the direction of the parting line and is easily accomplished in the mold. If a front to rear parting line were to be used for tines with wrap-around features, mold design would become complicated as the bore would then be perpendicular to the parting line. For this reason, most tines with wrap-around features use a lateral parting line. However, lateral parting lines make it difficult to achieve a deep enough section in the high stress area of the tine (in operation) with acceptable deflection characteristics in the normal direction of deflection.
Assuming a tine has a lateral parting line, deep depressions cannot be provided on the tine's front and/or rear surfaces, because they need to be smooth to release from the mold. If deep depressions are provided on the tine's lateral surfaces (i.e., in order to try to help even out the wall thicknesses for improved processing and to minimize weight), these cross sectional shapes would have poor deflection characteristics in the normal direction of deflection, and would have a tendency to twist sideways as opposed to the preferable stable front-to-rear deflection.